Lemur kinematic and substrate morphology data

An accident during arboreal locomotion can lead to risky falls, but little is known how primates, as adept arborealists, might change their locomotion to accommodate increased substrate height. By using more stable forms of locomotion on higher substrates, primates might avoid potentially fatal consequences. Using high-speed cameras, we recorded the quadrupedal locomotion of four wild lemur species – <em>Eulemur rubriventer</em>, <em>Eulemur rufifrons, Lemur catta, and Hapalemur aureus</em>. We quantified the diameter, orientation, and height of locomotor supports using remote sensors and tested the influence of these parameters on gait kinematics (N=112). Lemurs did not adjust stride speed, length, or frequency on substrates of varying height. However, <em>E. rubriventer</em> increased the mean number of supporting limbs on higher substrates, and lemurs overall decreased the use of unstable limb support patterns and increase the use of stable ones on higher substrates. Results suggest walking is a relatively safe form of locomotion for lemurs, resulting in only subtle changes in gait to increase stability on higher – i.e., riskier – substrates. Continued investigation of the impact of height on locomotion will be important to determine how animals assess risk in their environment and how they choose to use this information to move more safely.

树栖运动过程中发生意外可能引发极具危险性的坠落，但目前学界对作为熟练树栖者的灵长类动物如何调整运动模式以适配支撑基底高度提升的情况仍知之甚少。若在更高的支撑基底上采用更稳定的运动形式，灵长类或可规避潜在的致命后果。本研究借助高速摄像机，记录了4种野生狐猴的四足运动模式：红腹狐猴（*Eulemur rubriventer*）、红领狐猴（*Eulemur rufifrons*）、环尾狐猴（*Lemur catta*）以及金竹狐猴（*Hapalemur aureus*）。研究通过远程传感器量化了运动支撑物的直径、朝向与高度，并检验了这些参数对步态运动学的影响（样本量N=112）。在不同高度的支撑基底上，狐猴并未调整步速、步长或步频。不过，红腹狐猴（*E. rubriventer*）在更高的支撑基底上会增加支撑肢体的平均数量；整体而言，狐猴在高基底环境下会减少不稳定肢体支撑模式的使用，转而更多采用稳定的支撑模式。研究结果表明，行走对狐猴而言是一种相对安全的运动模式，仅需对步态做出细微调整，即可在更高——即风险更高——的支撑基底上提升运动稳定性。后续针对高度对运动模式影响的深入研究，对于探明动物如何评估所处环境中的风险，以及它们如何利用此类信息更安全地完成移动，具有重要的学术价值。